Apparatus for the treatment of tools and other small steel or steel alloy articles



C. J. THE TREATM 0F TOOLS AND OTHER SMALL LOY A an 4 Oct. 15, 1929.

RTICLES 1928 EELOR STEEL AL Orgngl Filed J APPARATUS NGA- Patented Oct.15, 1929 UNITED STATES PATENT OFFICE CHARLES JAMES GRIST, OF BERKSWELL,ENGLAND, ASSIGNOR OF FOUR-FIFTHS TO CHARLES WILLIAM ST. JOHN ROWLANDSON,F LONDON, ENGLAND APPARATUS FOR THE TREATMENT OF TOOLS AND OTHER SMALLSTEEL OR STEEL ALLOY ARTICLES Original application led January 4, 1928,Serial No. 244,474, and in Great Britain January 7, 1927. Divided andthis application filed December 5, 1928. Serial No. 324,038.

This invention relates to apparatus by means of which finished tools andother small steel or steel alloy articles can be heated to any desiredtemperature and afterwards cooled in a chamber, during which time acurrent or currents of electricity can be passed through the tools orother goods for the purpose of improving them by removing or modifyingthe disadvantageous results of stresses set up in the steel or metal ofwhich they are composed during their manufacture, and thereby enablingthem to perform the work required of them for a longer period of timeand to d0 given work of equal quality in a shorter period of time. Thisapplication is a division of the application filed by me on January 4,1928, Serial Number 244,47 4. f v

The invention' relates solely to the apparatus hereinafter described,namely apparatus for the purpose herein specified comprising anexternally heated chamber or receptacle, means, insulated from thechamber or receptacle and from each other, for holding a plurality oftools or other articles in said chamber or receptacle, and means forapplying an electric current t0 the tools or other articles supportedrin said chamber or receptacle. The said apparatus may be employed forutilizing the motive powers of heat and electricity beneficially uponfinished steel tools and other goods. The temperature to which any giventool or tools shall be raised, the medium surrounding it 0r them in thechamber in which they are being treated (whether gaseous liquid orsolid), the strength of the electric current and the duration of time itis applied, must necessarily be varied according to the chemicalcontents of the steel or iron of which the articles are composed, theirhistory, and the work they have to perform, and are determined byexperiments.

Fig. l of the accompanying illustrative drawings shows in centrallongitudinal vertical section a construction of apparatus embodying theinvention.

Fig. 2 shows the apparatus in plan.

Fig. 3 is an end elevation of the apparatus 50 with the end bailleplates removed.

Figs. 4 and 5 are vertical sectional elevations to a larger scaleshowing parts of the apparatus to which reference will be hereinaftermade.

In the drawings, which illustrative, by way of example only, oneconstruction of the apparatus, l indicates a chamber or receptacle madepreferably of wrought steel which may be or' any convenient shape butwhich is of rectangular shape in the construction shown. At its upperedge the rece*l tacle or chamber l has an outwardly extending flange 2which is formed with a marginal recess 3 adapted -to be engaged by amarginal spigot 4 projecting downwardly from a cover piate 5 which isadapted te be secured to the flange 2 by means of bolts passed throughholes 6 formed therefor in the cover 5 and flange 2. In order to providea tight joint between the cover 5 and receptacle l, the marginal spigot4 of the cover 5 bears on asbestos or other suitable material pacledinto the marginal recess 3 of the flange 2.

Eye bolts 52l are screwed into the cover 5 to facilitate its removal. 7indicates a hole in the cover 5 furnished with a gland through which athermic couple can be passed into the receptacle, the coid junction ofsaid couple being connected at the exterior ot' the apparatus to agalvanometer for the purpose of recording the temperature inside thereceptacle. Any number of tiiermic couples ma be inserted in the chamberaccording to its size and requirements. S indicates a tool holdingspindle that is passed through an insulating bush 9 provided therefor'in the cover 5. The bushes 9 insulate the tool holders from the chamberor receptacle and from each other. Each insulating bush, see F ig. 4,consists of a split ring 9 of asbestos or other suitable material havinga conical exterior on which bears the conical bore of a lock nut l()that is screwed into the hole formed therefor in the cover. By screwingdown the said nut on to the split ring 9 the spindle 8 is firmly held inthe required position so that the extent to which its lower end entersthe receptacle or chamber can be determined as desired according to thelength of the article being treated. At its lower end the tool holdingspindle 8 is fitted with a screw 11 or other suitable means for holdingthe tool or article tobe treated, and at its upper end aclip 12 or otherdevice is fitted on the spindle 8 whereby it may be connected readily toan electric conductor connected to the positive pole of a switch board,not shown. In axial alignment With the tool holding spindle 8 there isfixed on the bottom of the receptacle 1 a Contact device for the lowerend of the article carried by the spindle 8. rlhis device, see F ig. 5,consists of a self-centering cup 13 mounted in the upper end of ahelical spring 14 Which is carried in a holder 15 secured to the bottomof the receptacle. Any suitable means in electrical Contact with thereceptacle or chamber, such for example as a binding soresT 16, issecured to the receptacle or chamber 1 to receive a conductor cennectedto the negative pole of the beforementionedl switch board.

In the example of apparatus under notice the receptacle or chamber isheated by Bunsen flame burners 17 and the heat is conserved andradiation minimized by means of baille or mutlle plates 18 made say ofiron lined with asbestos, or other suitable material, and extendingentirely around the sides and'ends of the receptacle or chamber. rlhesaid baille or muilie plates may in some cases be made of irebrick orother refractory material.

The receptacle or chamber is supported on a centrally arranged support19 and on end supports 20, and the said end supports, which carry theinner baliie plates 18, may, as shown, be connected by the bolts 21.

In order to protect the bottom of the receptacle from the directiinpingement of the Bunsen burner flames, blocks 22 of iirebrick orother appropriate material can, if so desired, be xed to the bottom ofthe receptacle, as shown, over the Bunsen burners.

As before stated the receptacle or heating chamber can be of any desiredsize and shape and can be arranged to receive any desired number oftools or articles to be treated.

The apparatus illustrated is particularly suitable for treating articlessuch as steel tools and is designed to treat say twenty-seven of sucharticles at one time, there being that number of tool holding s iindlesfitted in the cover and that number of self-centering cups fixed to thebottom of the receptacle. As will be understood variations in details ofdesign and construction can be made Without departure from theinvention.

llhe electrical switch board hereinbeforeL mentioned but not shown inthe drawings, is of any appropriate type and is provided with contactsconnected to the several holders 12, the said contacts being lconnectedto a source of current as by switch levers, either individually or ingroups so that an electric current can be applied to each toolseparately or to any desired number or to all of the toolssimultaneously, at and for any given period of time.

What I claim is 1. Apparatus for use in the treatment of finished toolsof steel or steel alloys, comprising an externally heated receptacle, acover for said receptacle, means for making a tight joint between saidreceptacle and said cover, tool holders insulated from and extendingthrough said cover into said receptacle, devices Within sai-d receptaclethat make electrical contact With tools carried by Vsaid tool holders,means for heating said receptacle, and means for placing said toolholders and said Contact devices in connection With a source of electriccurrent so that an electric circuit is completed through the toolscarried by said tool holders within said receptacle.

2. Apparatus for use in the treatment of finished tools of steel orsteel alloys, comprising a receptacle, a cover for same, means formaking a tight joint bet-Ween said receptacle and said cover, bushes ofinsulating material fitted in said cover, tool holders extending throughsaid bushes into said receptacle, con z tact devices adapted to receivethe ends of tools carried by saidl tool holders, said contact devicesbeing constitutedv by self-centering cups fixed to the bottom of saidreceptacle one in line with each of said insulating bushes, means forheating said receptacle, and means for placing said tool holders andsaid contac devices in connection with a source of elect-rie current sothat an electric circuit is completed through the tools carried by saidtool holders within saidreceptacle.

3. Apparatus as claimed in claim 2 in which the contact devices for thetools carried by the tool holders, each consist of a metal cup carriedVby a helical spring that is mounted4 in a suitable holder lixed to thebottom of the receptacle n l. Apparatus for treating metal articles,comprising a furnace air chamber, holders Y for the articles projectingvertically through t-he top of the furnace air chamber and insulatedfrom it, Contact pieces at the bottom of the furnace air chamber forvthe articles to rest on, means for passing an electric current throughthe' articles and holders,and means for heating the furnace air chamberexternally.

5. Apparatus for treating metal articles as set forth in claim 4, theholders for the articles being slidable in the top of the furnace airchamber and being provided With means for clamping them when theirpositions have been adjusted vertically.

ln testimony whereofl aiiix my signature.

CHARLES JAMES GRIST. Y

